Commercial HVAC systems may have a contained “Fan Coil” (“FC”) for the purpose of providing an outlet for commercial ventilation systems into the rooms of a building or other structure equipped with an HVAC system. An FC typically consists of the following components: 1) centrifugal fan, 2) motor, 3) insulated casing, 4) air inlet (with or without damper), and 5) Heating/Cooling Coils.
In commercial HVAC installations, a “silencer” (or “attenuator”) is often attached to the inlet or outlet of an FC in order to attenuate the sound produced by the high-velocity air entering the FC. Such silencers have typically comprised an air duct (typically from three to five feet in length) that is lined internally with insulation to attenuate the noise produced by the air flowing through the FC. Such internal insulation is also known as a “baffle” and is usually held in place by perforated sheet metal. The perforations in the metal allow the air traveling through the silencer to interact with the insulation material contained inside the baffle. The silencer is attached to the inlet or the outlet of the FC and acts to attenuate the noise that is produced by the FC. This attenuation is achieved due to the conversion of acoustic energy into heat energy as the air molecules inside the silencer create friction when they collide with the lined insulation.
The noise generated by an FC or other HVAC component can be separated into two components: 1) noise due to the air disturbance created in the immediate vicinity of the rotating fan blades and 2) aerodynamic noise due to the fan-induced air flow that has variable pressure regions within the fan discharge velocity profile and the air flow interaction with geometry changes in the air stream. The insulation contained in silencers is typically designed to minimize both sources of noise.
There is a need for an improved silencer, particularly one which is compact, efficient and durable.
Fan Coil units are capable of producing condensate carryover when applied in higher humidity conditions. This design helps prevent carryover as an integral part of the unit.